re PR tree-optimization/46590 (long compile time with -O2 and many loops)

PR tree-optimization/46590
	* cfgexpand.c: Revert last change (r183305).
	* gimplify.c (gimplify_bind_expr): Add clobbers for all non-gimple
	regs.
	* tree-eh.c (cleanup_empty_eh): Try to optimize clobbers before
	checking for emptiness.

From-SVN: r183566

gcc/ChangeLog

@@ -1,3 +1,12 @@
+2012-01-26  Michael Matz  <matz@suse.de>
+
+	PR tree-optimization/46590
+	* cfgexpand.c: Revert last change (r183305).
+	* gimplify.c (gimplify_bind_expr): Add clobbers for all non-gimple
+	regs.
+	* tree-eh.c (cleanup_empty_eh): Try to optimize clobbers before
+	checking for emptiness.
+
 2012-01-26  Jakub Jelinek  <jakub@redhat.com>
 
 	PR middle-end/51895

gcc/cfgexpand.c

@@ -440,12 +440,11 @@ visit_conflict (gimple stmt ATTRIBUTE_UNUSED, tree op, void *data)
 
 /* Helper routine for add_scope_conflicts, calculating the active partitions
    at the end of BB, leaving the result in WORK.  We're called to generate
-   conflicts when OLD_CONFLICTS is non-null, otherwise we're just tracking
+   conflicts when FOR_CONFLICT is true, otherwise we're just tracking
-   liveness.  If we generate conflicts then OLD_CONFLICTS stores the bits
+   liveness.  */
-   for which we generated conflicts already.  */
 
 static void
-add_scope_conflicts_1 (basic_block bb, bitmap work, bitmap old_conflicts)
+add_scope_conflicts_1 (basic_block bb, bitmap work, bool for_conflict)
 {
   edge e;
   edge_iterator ei;
@@ -482,7 +481,7 @@ add_scope_conflicts_1 (basic_block bb, bitmap work, bitmap old_conflicts)
 	}
       else if (!is_gimple_debug (stmt))
 	{
-	  if (old_conflicts
+	  if (for_conflict
 	      && visit == visit_op)
 	    {
 	      /* If this is the first real instruction in this BB we need
@@ -490,27 +489,16 @@ add_scope_conflicts_1 (basic_block bb, bitmap work, bitmap old_conflicts)
 		 Unlike classical liveness for named objects we can't
 		 rely on seeing a def/use of the names we're interested in.
 		 There might merely be indirect loads/stores.  We'd not add any
-		 conflicts for such partitions.  We know that we generated
+		 conflicts for such partitions.  */
-		 conflicts between all partitions in old_conflicts already,
-		 so we need to generate only the new ones, avoiding to
-		 repeatedly pay the O(N^2) cost for each basic block.  */
 	      bitmap_iterator bi;
 	      unsigned i;
-
+	      EXECUTE_IF_SET_IN_BITMAP (work, 0, i, bi)
-	      EXECUTE_IF_AND_COMPL_IN_BITMAP (work, old_conflicts, 0, i, bi)
 		{
 		  unsigned j;
 		  bitmap_iterator bj;
-		  /* First the conflicts between new and old_conflicts.  */
+		  EXECUTE_IF_SET_IN_BITMAP (work, i + 1, j, bj)
-		  EXECUTE_IF_SET_IN_BITMAP (old_conflicts, 0, j, bj)
-		    add_stack_var_conflict (i, j);
-		  /* Then the conflicts between only the new members.  */
-		  EXECUTE_IF_AND_COMPL_IN_BITMAP (work, old_conflicts, i + 1,
-						  j, bj)
 		    add_stack_var_conflict (i, j);
 		}
-	      /* And remember for the next basic block.  */
-	      bitmap_ior_into (old_conflicts, work);
 	      visit = visit_conflict;
 	    }
 	  walk_stmt_load_store_addr_ops (stmt, work, visit, visit, visit);
@@ -527,7 +515,6 @@ add_scope_conflicts (void)
   basic_block bb;
   bool changed;
   bitmap work = BITMAP_ALLOC (NULL);
-  bitmap old_conflicts;
 
   /* We approximate the live range of a stack variable by taking the first
      mention of its name as starting point(s), and by the end-of-scope
@@ -549,18 +536,15 @@ add_scope_conflicts (void)
       FOR_EACH_BB (bb)
 	{
 	  bitmap active = (bitmap)bb->aux;
-	  add_scope_conflicts_1 (bb, work, NULL);
+	  add_scope_conflicts_1 (bb, work, false);
 	  if (bitmap_ior_into (active, work))
 	    changed = true;
 	}
     }
 
-  old_conflicts = BITMAP_ALLOC (NULL);
-
   FOR_EACH_BB (bb)
-    add_scope_conflicts_1 (bb, work, old_conflicts);
+    add_scope_conflicts_1 (bb, work, true);
 
-  BITMAP_FREE (old_conflicts);
   BITMAP_FREE (work);
   FOR_ALL_BB (bb)
     BITMAP_FREE (bb->aux);

gcc/gimplify.c

@@ -1231,7 +1231,7 @@ gimplify_bind_expr (tree *expr_p, gimple_seq *pre_p)
 	  && !DECL_HAS_VALUE_EXPR_P (t)
 	  /* Only care for variables that have to be in memory.  Others
 	     will be rewritten into SSA names, hence moved to the top-level.  */
-	  && needs_to_live_in_memory (t))
+	  && !is_gimple_reg (t))
 	{
 	  tree clobber = build_constructor (TREE_TYPE (t), NULL);
 	  TREE_THIS_VOLATILE (clobber) = 1;

gcc/tree-eh.c

@@ -4056,6 +4056,7 @@ cleanup_empty_eh (eh_landing_pad lp)
   edge_iterator ei;
   edge e, e_out;
   bool has_non_eh_pred;
+  bool ret = false;
   int new_lp_nr;
 
   /* There can be zero or one edges out of BB.  This is the quickest test.  */
@@ -4070,6 +4071,16 @@ cleanup_empty_eh (eh_landing_pad lp)
     default:
       return false;
     }
+
+  resx = last_stmt (bb);
+  if (resx && is_gimple_resx (resx))
+    {
+      if (stmt_can_throw_external (resx))
+	optimize_clobbers (bb);
+      else if (sink_clobbers (bb))
+	ret = true;
+    }
+
   gsi = gsi_after_labels (bb);
 
   /* Make sure to skip debug statements.  */
@@ -4081,9 +4092,9 @@ cleanup_empty_eh (eh_landing_pad lp)
     {
       /* For the degenerate case of an infinite loop bail out.  */
       if (infinite_empty_loop_p (e_out))
-	return false;
+	return ret;
 
-      return cleanup_empty_eh_unsplit (bb, e_out, lp);
+      return ret | cleanup_empty_eh_unsplit (bb, e_out, lp);
     }
 
   /* The block should consist only of a single RESX statement, modulo a
@@ -4096,7 +4107,7 @@ cleanup_empty_eh (eh_landing_pad lp)
       resx = gsi_stmt (gsi);
     }
   if (!is_gimple_resx (resx))
-    return false;
+    return ret;
   gcc_assert (gsi_one_before_end_p (gsi));
 
   /* Determine if there are non-EH edges, or resx edges into the handler.  */
@@ -4172,7 +4183,7 @@ cleanup_empty_eh (eh_landing_pad lp)
       return true;
     }
 
-  return false;
+  return ret;
 
  succeed:
   if (dump_file && (dump_flags & TDF_DETAILS))